A variety of exercise apparatus exists which allow the user to exercise by simulating a striding motion. Some of these devices also allow a stepping motion. For example, U.S. Pat. No. 5,000,443 illustrates a striding exerciser having right and left foot pedals, each fixedly attached to a lower end of a corresponding one of right and left swing arms. The swing arms each have an upper end pivotally attached to a frame. The user stands on the right and left pedals and exercises by swinging his legs back and forth to simulate striding. Each of the pedals is able to move rearward and forward along a manufacturer defined arcuate path about the pivot axis of the upper end of the swing arm which carries the pedal. A cable interconnects the right and left swing arms such that when one pedal moves rearward the other is moved forward, and vice versa, to provide a dependent reciprocal swinging action. The exerciser allows the user to use a stride length when exercising that is natural to the user, but the motion of the foot pedals and thus the user's foot thereon is constrained to a reciprocating motion along the simple arcuate path with no significant variation in pedal angle simulating stride height (heel lift) possible. To experience a change in foot angle during a stride which has a heel lift more natural to a striding motion, a user must lift his foot at least partially off the pedal or rock his foot on the pedal.
A similar striding exerciser shown in U.S. Pat. No. 5,613,924 which utilizes right and left swing arms which pivot independent of each other. Again, the foot pedals are constrained to move along a simple arcuate path with no significant variation in stride height.
A different style design for a striding exerciser is shown in U.S. Pat. Nos. 5,242,343; 5,383,829; 5,518,473 and 5,562,574. In these exercisers the right and left foot pedals are carried on a corresponding one of right and left foot links, each foot link having one end attached to a corresponding one of right and left bell cranks of a fly wheel. The other end of each foot link is guided by a corresponding one of right and left tracks or suspended by a corresponding one of right and left swing arms. With this arrangement, an ovate, open foot path is possible such that when exercising on the apparatus the user experiences a stride that has both a stride length and a stride height. A limited degree of adjustability is provided in at least one disclosed embodiment to adjust the incline of the foot pedals prior to commencing an exercise by use of connector pins and a plurality of pin receiver holes, with the adjustment being made before the exercise begins. However, with these exercisers, the stride length and stride height of the user is determined entirely by the construction of the exerciser with no variability for the natural stride length or height of a particular user. Further, there is no ability to vary the stride length or height while an exercise is in progress in response to the user naturally or by choice changing his stride length or height. Users of varying sizes and with different natural stride lengths and heights must all move their feet along the same manufacturer defined ovate path.
A striding exerciser which permits the user to stride using his natural stride length and stride height is shown in U.S. Pat. Nos. 5,299,993 and 5,499,596. In the disclosed exerciser, the right and left pedals are each supported on a corresponding one of right and left articulated linkage assemblies. Each linkage assembly includes a generally vertical arm having an upper end pivotally attached to a frame and a lower end pivotally attached to a forward end of a generally horizontal arm comprising a pair of arm members in four bar arrangement. The free rearward end of the generally horizontal arm supports one of the foot pedals. The exerciser uses rollers below each horizontal arm to support the arm from below and limit downward travel thereof when the user's weight is applied to the pedal carried by the arm. The right and left linkage assemblies operate independent of each other and allow the user to move his feet with a natural stride length and stride height while exercising without being constrained to a fixed manufacturer defined pedal path. The exerciser, however, has a less than desirable construction and operation. Further, in one disclosed embodiment, the vertical arms are coupled to a crank assembly which undesirably constrains the user to a fixed stride length which may not simulate the natural stride length of the user.
It will, therefore, be appreciated that there has been a need for a striding exerciser which can be used for striding exercises such as walking, jogging and running, and stepping in place exercises which accommodates the natural stride length and stride height of the user, and does not constrain the user to a fixed stride length or height which may not match the user. The exerciser should allow the user to change the stride length and height being used during the progress of an exercise without requiring the user to adjust equipment settings. Such a striding exerciser should provide a strong and durable construction and operate with an exercise feel which is more desirable to users than presently available striding exercisers. The present invention fulfills these needs and further provides other related advantages.